In the field of Purpose Built Backup Appliance (PBBA), de-duplication is one of the key techniques. De-duplication is a data compressing operation which intends to remove duplicated data and only back up new data before backing up the data to the backup device, and thereby efficiently reduces occupancy of the repeated/duplicated data in the storage space. De-duplication is a compute intensive process, and includes algorithms of data segmentation, data fingerprint compute, fingerprint index search, etc. Furthermore, as per user requirements, backup appliances usually provide options to compress and encrypt data. High-end CPUs may be used to achieve the purpose. However, such kind of CPUs is very expensive and not suitable for wide use. On the other hand, the software-based solution also contains lots of defects in the aspects of cost, application range and performance.